Cited Document 1 discloses a configuration of a signal processing circuit constituted by N-channel transistors (see (B) of FIG. 19). The signal processing circuit includes a bootstrap circuit. In a case where a signal supplied to a terminal 2 becomes active (High), a signal (clock signal or power supply signal) supplied to a terminal 1 is outputted from a terminal 4 (output terminal) (because of a bootstrap effect, the signal processing circuit can output a signal which is not less than a threshold). In a case where a signal supplied to a terminal 3 becomes active (High), a VSS (Low) is outputted from the terminal 4 (output terminal).